Mazda BT-50 2011 Problems

It’s possibly a faulty sensor sending the wrong signal to the ECM. Have it checked by your dealer or mechanic.

Without being able to view it and hear it firsthand it's hard to suggest what might be wrong. It could be a bearing in the turbo, but that's only an educated guess. I would have a mechanic check it.

There are a number of heavy trucks running dual-fuel systems with a blend of diesel and natural gas, on some the gas is compressed (CNG) and on others it's liquefied (LNG). There are also other heavy truck systems that use diesel and LPG. We have reported on all of them over the past couple of years. In the case of light commercial vehicles the systems employed use diesel and LPG, substituting LPG for diesel, and as you say it needs to be very carefully controlled. The more LPG you use the more power you will get, but if it's not well controlled you run the risk of damaging the engine and that's very costly.

On the surface, you’d probably start looking at the car’s fuel system. A diesel, even a modern one, is controlled largely by how much fuel is being pumped into it and at what pressure. If the fuel pump is slack or the injectors, filters or lines are faulty or leaking, you might find that there’s simply not enough fuel to keep it revving on beyond that 2200rpm.

But you could also be looking at an exhaust problem, a partially blocked intake system, dirty air filter, or even a worn out turbocharger. A mechanic who is familiar with this make and model is going to have the best chance of diagnosing what’s wrong. Chances are yours is not the first vehicle to do this, and a specialist mechanic has possibly seen it all before.

Mazda tell us they have come across cam belt failures on the BT-50, but that it wasn't what they would refer to as a common concern, and not one they consider to have an abnormal rate of failure. From that you could deduce that it's not an unusual failure, but the failure rate isn't sufficiently high to do anything about.

Jumping out of fifth gear is a common problem on early BT50s, but a fix was supposed to have been introduced in late 2007. I agree that Mazda should bear at least some of the cost of the repairs so take it to a Mazda dealer and submit a claim.

I would urge caution. These systems work by substituting a percentage of the diesel fuel with LPG and do deliver more power or better fuel economy depending on how you drive the car. The general idea is that you don't have to depress the throttle as far to get the same performance and you can then realize some fuel consumption savings, but I have had quite a number of reports of serious engine meltdowns because the driver simply couldn't resist the temptation to keep the foot down on the throttle. My concern is also that there isn't the same experience with these systems as there is with dual-fuel systems on petrol engines, so they're more exposed to problems. Before you do it talk to other owners about their experience with the systems.

We haven't heard of belt failures like you report, but it would be good to hear from any of our readers who have suffered the problem. It sounds like a serious one.

The smart money here suggests that there’s something your car’s electrical system and body computer don’t like about replacement LED lights. That’s assuming you’ve installed them correctly, of course. The first thing you should do is replace the standard globes and see if that restores the lights’ operation. If it does, you can be reasonably sure there’s a problem with the way the car reacts to the LED replacements.

Not all cars appreciate the conversion to LEDs. These newer lights draw a lot less current than conventional globes and, while that sounds like a good thing, the lack of current-draw detected by the body computer can cause problems. Another common problem with LEDs is that the low current-draw makes the car’s computer think that there’s a blown globe at which point it can trigger a warning light on the dashboard.